Meta-information is information used for reading video streams, and indicates the address and the size of each piece of picture data that is independently decodable. In MPEG2 (Moving Picture Experts Group phase 2), MPEG4-AVC (Advanced Video Coding,) and so on, meta-information generation technique is indispensable for particular kinds of playback operation for playing back video streams that have been encoded using correlation among frames. Accordingly, the meta-information generation technique is adopted in the application layer standard of various recording media.
Since video streams encoded in accordance with an encoding method such as the MPEG2-Video and the MPEG4-AVC are compressed using the correlation among the frames, it is impossible to decode a P picture and a B picture until a picture data that is independently decodable is decoded. Therefore, a playback apparatus reads meta-information to interpret how much data should be read and from which position the data should be read. As a result, the playback apparatus can immediately judge where to start reading of the video stream to play back the independently-decodable picture data, without actually analyzing the content of the video stream. In this way, it is possible to read independently-decodable pictures one by one by using the meta-information without reading unnecessary data. As a result, in the case where video data is recorded in a recording medium, random access such as fast-forward playback and reverse playback can be appropriately realized.
Note that Japanese Laid-open Patent Application Publication No. 2000-224543 discloses a prior art relating to the meta-information generation technique.